1. Field of the Invention
The present invention relates to a method of manufacturing a liquid ejection head.
2. Description of the Related Art
An ink jet printer ejecting an ink is widely known as a recording device which ejects liquid to perform a recording operation. A liquid ejection head used for the recording device includes a liquid-ejection-head substrate and a flow path member. The liquid-ejection-head substrate includes energy generating elements for generating energy to eject liquid. The flow path member forms ejection orifices and a part of a flow path for the liquid. The liquid-ejection-head substrate is provided with electrode pads for transmitting an electric signal from a member different from the liquid-ejection-head substrate to the liquid-ejection-head substrate. Moreover, a supply port for supplying the liquid to the energy generating elements is provided to the liquid-ejection-head substrate so as to pass through the liquid-ejection-head substrate.
As a method of manufacturing the liquid ejection head, for example, a method disclosed in Japanese Patent Application Laid-Open No. 2009-61665 is given. Specifically, in the method, a substrate provided with an alkali-resistant protective layer is prepared. After a flow path member is formed on the substrate, a laser pattern is created so as to pass through the protective layer and engrave the substrate by a given amount. Then, the substrate is etched with an alkaline liquid through the created laser pattern.
According to the method disclosed in Japanese Patent Application Laid-Open No. 2009-61665, a damage is caused in the alkali-resistant protective layer in the process from after the formation of the alkali-resistant protective layer to the completion of the formation of the flow path member. This may expose the substrate which lies under the alkali-resistant protective layer. If the supply port is formed in this state, the alkaline liquid passes through the damage in the alkali-resistant protective layer to disadvantageously etch the substrate. As a result, a processed shape of the supply port is enlarged or an unintended processed hole is formed in some cases. Therefore, the quality of the liquid ejection head is required to be further improved.